Sun Pro and Sun Choice Dual Fuel Rooftop Units Switch Between Fuel Sources

YORK, a licensed brand of Bosch Home Comfort Group, has launched the Sun Pro and Sun Choice Dual Fuel Rooftop Units, which combine a heat pump with a gas or propane furnace as a supplemental heat source to deliver efficient heating and cooling year-round in light commercial applications. Building owners in colder climates can reduce utility spending and support long-term energy goals while reliably maintaining occupant comfort. The transition between fuel sources is automated through controls that enable operators to set a balance point to determine the outside temperature at which the system transitions between heat pump heat and gas heat to maximize comfort and efficiency. The balance point can be customized to prioritize comfort or lower emissions.

A backup heat setting allows the unit to engage either source of heat when there is a lockout or failure with the other source, ensuring at least some heat is provided to the space in all conditions. Optional hot gas reheat helps control humidity. Units also feature a dual-circuit design for refrigerant; if one circuit has a refrigerant leak or compressor issue, the system operates at 50% capacity until it can be serviced. The Sun Pro model comes in capacities of 6.5 to 12.5 tons, while Sun Choice features capacities of 12.5 to 25 tons.